Having been a TEV product mangler in my past life, yes I've seen this before. It is not common, however.

With a heat pump system in the heating mode, and if a TEV is used to feed the indoor coil, discharge pressure will be transmitted to the underside of its diaphragm via the equalizer line.

Normally this is not a problem for the valve.

But if a recip compressor is being used, and if the recip compressor is delivering an inordinate amount of discharge pulsations... these pulsations work on the TEV powerhead. The powerheat casing flexes ever so slightly with these pulsations as if it were a drum. The weld succumbs... :(